Problems Description
<p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;">我们定义一items数列<span>F(n)</span><span>代表</span><span>n</span><span>的有序拆points数:</span></span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;">比如</span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal" style="text-indent:37.2000pt;"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;">3=3 </span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"> 3=1+2 </span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"> 3=2+1 </span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"> 3=1+1+1</span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;">3<span>的有序拆points数为</span><span>4</span><span>种。</span></span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;">再比如</span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"> 4=4</span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"> 4=1+3</span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"> 4=3+1</span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"> 4=2+2</span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"> 4=1+1+2</span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"> 4=1+2+1</span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"> 4=2+1+1</span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"> 4=1+1+1+1</span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;">4<span>的有序拆points数有</span><span>8</span><span>种,当然我们很容易发现</span><span>F(n)=2^(n-1)</span><span>,所以咱们的题目肯定不可能是这么简单的。现在我想问的是,给定任意两items数</span><span>n</span><span>和</span><span>k</span><span>,求</span><span>n</span><span>的所有拆points情况中,</span><span>k</span><span>出现的次数是多少。</span></span><span style="font-family:宋体;font-weight:bold;font-size:15.0000pt;"></span> </p>
Input格式
<p class="MsoNormal"> <span style="font-family:宋体;font-size:12.0000pt;">输入File包含多组测试数据。Page 一行,给出一items整数 <span>T</span><span>(</span><span>T<=20</span><span>),为数据组数。</span></span><span style="font-family:Calibri;font-size:12.0000pt;"></span> </p> <p class="MsoNormal"> <span style="font-family:宋体;font-size:12.0000pt;">接下来有一行,points别输入两items数<span>n,k</span><span>(</span><span>1<=n,k<=10^9</span><span>)</span></span><span style="font-family:宋体;font-size:12.0000pt;"></span> </p>
Output格式
<p class="MsoNormal"> <span style="font-family:宋体;font-size:12.0000pt;">输出结果并对<span>1e9+7</span><span>取余</span></span><span style="font-family:Calibri;font-size:12.0000pt;"></span> </p>
Sample
Sample Input 1
2
4 2
5 5
Sample Output 1
5
1
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